Method of installing sheet piling



Dec. 8, 1931. A. P. MILLER METHOD OF INSTALLING SHEET FILING Filed June15, 1931 2 Sheets-Sheet l iNVENTOR D86. 8, 1931 p I 1,835,665

METHOD OF INSTALLING SHEET FILING F le J ne 1931 2 Sheets-Sheet 2Patented Dec. 8, 1931 FATENT QFF CE METHOD or rnsTA L Nesnrm FILING Apli ation me Jan '15 The present invention is concerned with a method ofinstalling sheet considered from one asp ct capable of a wide and variedrange of utility in connection with sheet piling installationsregardless of the purpose for which the piling is to used,

Considered from another hovvever,

the invention is generically concerned with the provision of a nethodiof sheet piling installation \vhich vvill obviate the need forshoring or under-pinning abuilding during the P e s of i gi al e c? atiadiee t thereto. w i

In other ords, whilethe method of piling installation completelyobviates the present undesirable methods of jetting or driving the sheetpiling, it is unique in that it is the only method thus far devisedforelfeqtively eliminating the need for under-pinning or shoring \vherean excavation is to be made deep or deeper thaithe footings of:adjacentstanding structures. i

Driving methods of installing sheet pilings create vibration Waves whichspreadto adjoining foundat ons, causing settlement,

crackinglor crumbling of these foundations.

Also, the norse .att ending".such' percussive means ofinstallingsheetipilings quite annoying. I i l v Water jetting methods ofinstalling any type of piling's are frequently disa dva ntageousinasmuch as they cause 'settlement of the surrounding soil, and therebyendanger the foundations oiisurrounding structures. Such methods alsoentail the use of ,puiiiping units for creating high pressure jets andthe splashing and splatteringof the ater attending such a method causesa messy condition around the construction region.

An object of the present invention therefore is to provide a method bywhich sheet pilings may be installed .in asi npleand inexpensive mannerwithout the use ofeither driving or jetting apparatus which mightsubject the soil to excessive vibrations, or cause undesirablesettlement thereof.

Another object is to provide amethod of installing foundations closelyadjacent a previously erected building wherein sheet e s 'tiqn f Pi i ispl e 1S us d and 1:13;- e e ec- 24 4- pre tested as it is installed, thepretesting being suliicient to determine Whether or not the individualsheet piling'sections are capable of sustaining their share of the loadwhich will be eventually transmitted "as them through the soil by theadjacent structure Another object' 'of the invention isto provide amethod 01 piling installation wherein the possibility of displacementorcaving in the pretested sheet piling is further e1 bracing memberswhich are appliedatinr tervals' as the excavation proceeds. Thesesupplemental bracing members may be and theoretically are merely anadded safety factor, but by utilizing them the span of tlile sheetpiling in which flexing may occur is considerablylininimized. i

In carrying out my invention, Isinl; shafts one at a time in the soilalong the boundary 1 line of the proposed excavation as by the useot'conventional post hole angers. The sllfiit pilings which are avidthcorrespondinga}? proximately to the diameters ofthe shafts or holesare then dropped into the their lower ends embedded in the soil .toafford a toe-hold. The topportions of the edge keyed pilings are thenbraced against lateral movement'by the use of a ivaler,"or the like, andthe cavities defined by the outside c surfaces of the pilings and thecorrespondouter Wallsof the $11; ts are filled in with part or thepreviously removed soil or other "suitable material. This fillermaterial is tamped or otherwise compacted,

ivill exert a v ing toivard the area to be excavated so that thesepilings will be stressed sufiiciei tlyt o counteract'the effectofpressure exerted by surrounding structures. l After the sheet pilingshave been so installed a-11dpretestcd,tl1e excavation can then bestarted, the intermediate portions of the sheet piling being furtherbraced against unduednward flexing as the excavation proceeds. Inotherhwo'rds, having installedand vpretested the sheet piling as to itsload carryability, and having thus ascertained the fact that the sheetpiling'will sustain the load, even when flexed throughout the entireided against by the use of suppleiiiel ital holes with so that it R ..1'1 '1 lateral piessuieon saic. saee p1 length -:of its span Ibetweenwaler at the surface of the ground and the bottom emheddedportionthereof, an added safety factor is provided by the installation oflateral bracing members emplaced as the excavation proceeds, thesebracing members serving to subdivide the maximum flexed span of thepiling into a plurality of smaller spans which can even more effectivelysustain the load of the adjacent structures. Preferably the nature ofthe bracing structure is such that it would sustain the loadstransmitted laterally and downwardly through the soil, even though thesheet piling was unkeyed, and even though it had no toe-hold.

This method of eliminating shoring and underpinning, while capable ofuse in any type of soil, is peculiarly adapted for use in water-bearingsand, such for instance, as beach sand, since the pretesting of thepiling is materially expedited due to the facility with which the sandmay be packed in behind the pilings and tamped for pretesting purposes.Furthermore, the installation of a foundation in water-bearing sandwhere conventional well points are used to dewater the sand at theexcavation site, is conducive to an actual flow of sand underasubadjacent structure toward the excavation. In the present instance,the sheet piling, while permitting thefree flow of water toward the Wellpoints from which it was pumped to dry the soil, acts as a positivepreventative of the flow of sand with the water.

In the accompanying drawings, there is shown for the purpose ofillustration, one specific form by which the present inventlon may becarried out. In these drawings Fig. '1 is a diagrammatic top plan viewof the proposed excavation region adjacent a standing structure.

Fig. 2 is a section taken onthe line 22 of Fig. 1, and showing the linesof force radlating from the foot of structures ad oining the excavation.

section of the sheet piling in position.

Fig. 5 is a section transverse to that shown in Fig. 4, and showing thesoil packed in behind the pilingsection to pretest the latter.

Fig. 6 is a vertical section through an area in which the excavation hasalready been accomplished, and V Fig. 7 is a section taken on line 77 ofV Fig. 6, and showing the process of concreting the wall of thecompleted excavation.

In Figs. 1 and 2, I have shown the area A representing the area of theproposed excavation, this area. being adjacent a heavy standingstructure, such as the building B.

The weight of the building B is distributed through the soil as a forceacting approximately in the directions indicated by the lines C, itbeing understood that the particular angle of load distribution throughthe soil will be determined to a large extent by the nature of the soilitself. The forces acting through the vertical plane indicated by theheavy line D, which represents that proposed wall of the proposedexcavation nearest the building B, would tend to cause the soil underthe footing of the building B to move laterally into the excavated areawhen the reactionary forces exerted by the soil itself, are destroyed bythe process of excavation. Consequently some means must be providedeither to support the footing of the building A during the period ofexcavation, or some other means must be provided for effectivelycounteracting the forces indicated by the lines C and thereby preventinginflow of soil into the excavation and settlement or collapse of thebuilding.

Prior to the present invention, it has been customary either to underpinthe building where the excavation was to be made considerably deeperthan the footings of the standing structure, or to support the buildingby shoring orequivalent bracing means.

Insofar as I am aware, the use of sheet pilings to line the walls of theproposed excavation for the purposes of preventing undermining orsettlement of an adjacent structure, has not heretofore beensatisfactory or safe, principally because there was no method of safelyutilizing such pilings with any assurance thatthey would preventcollapse of the excavation or settlement of the building. Furthermore,the methods which have been previously used for installing sheet pilingwere in themselves not of a character which would permit'piling to besafely used in'lieu of underpinning or shoring. That is to say, the useof percussive means or of jetting means, might create disturbances inthe soil under the standing structure and cause settlement thereofbefore excavation work was ever started. Furthermore, by prior methodsof sheet piling installation, the engineers in charge of excavation,have not been able to assure themselves that the sheet piling wouldcarry the lateral load imposed upon it since there has heretofore beenno method of protesting the ability of the piling to carry the load.

pretested as an incident of its installation so that the ability of thepiling to carry the load has been proven before any actual excavationwork is started.

In accordance with the method, the first mamas step is to drill a shaftsuch as E with its center on the line D which is the side line of theproposed excavation. This shaft may be formed with an ordinary post holedigger or auger F, or by any other convenient means, the diameter of theshaft being substantially equal to the width of the sheet pilingsect-ion to be installed.

The depth of this shaft would depend on the desired depth to which theexcavation is to be made, but should preferably extend below the bottomof the excavation, since the bottom of this shaft would have a layer ofloose soil collected thereat as the result of the falling or flow ofthis soil during the boring process and pile installation. Also, byforming a shaft E which eXtends below the bottom of the excavation, thelower portion of the sheet piling subsequently installed therein willhave the lower end thereof firmly held and embedded below said bottom ofthe excavation, so that when the excavation is accomplished, the lowerend of the sheet piling will still be retained in firm. anchoredposition. A small amount of soil may be dumped in and tamped if desired,to form the toe hold.

After the shaft E has been formed in the soil, a sheet piling G islowered therein. Although this sheet piling may be of wood or concrete.it is preferable, for the purpose of the present invention, that it bemade of steel, and may be of the usual form having means along the edgesthereof for interlocking it with or keying it to adjacent sections. Thesheet piling G is disposed in the shaft E in substantially verticalposition and the lower end thereof embedded in the soil at the base ofsaid shaft. Since the soil at the bottom of the shaft E includes loosesoil which has fallen or flowed therein during the formation of saidshaft or fallen during placing of pile, the lower end of thesheetpilings G will be very easily embedded in this loose soil. If desired,pressure may be applied to the upper end of the sheet piling to embedthe lower end of the piling in the firm compact ground.

Furthermore, the momentum and weight of the steel piling as it isdropped into the excavation, causes the foot of the piling to embetitself in the soil, usually .to a sufficient extent to form an effectivetoe-hold. It will be understood that the weight of the building will beineffective to cause collapse of the walls of the shaft E due to thefact that the soil which encircles this shaft has a true arch effect andefficiently carries the weight of the buildin A number of these sheetpilings E may be similarly installed by boring a'correspondnumber ofshafts sufiiciently close to each other to permit interengagement of the'longitudinal edges of adjoining sheet pilings disposed therein. After-anumber of-such sheet greater resultant stress from the pro exerted bythe structure B,.and also have a pilings have been installed, the upperends thereof may be maintained in aligned anchored position, and bracedagainst inward deflection towards the excavation region A by a suitablebracing member such as a wale piece H.

After the sheet pilings G have been so installed, the spaces J definedby the outer faces of said sheet pilings and the corresponding walls ofthe shafts E are filled with packing material. Although these spaces Jmay be filled before the upper ends of the piliugs are braced andanchored in position, it is preferable that both ends of the pilings beanchored in position before the filling operation is begun. The fillermaterial may consist of soil previously taken from the boring of theshaft E, or if desired, a dry mixture of COL- c ete may be substituted.This filling material in the spaces J is then packed very firmly inorder to stress the sheet pilings suliiciently for them to exertreactionary forces WAlCll balance the forces created by the structure B.For that purpose, the filling material may be packed by means of astandard tamping tool, a piece of lumber, by the puddling of water, orby other similar means. The stress exerted by the packing of thisfilling material in the spaces J will cause slight defiections of thepilings, the span of the defied tion being determined by the distancebetween the wale piece H and the toe hold of the piling in the soil,shown somewhat exaggerated in Fig. 5.

If desired, as each shaft is bor d and the piling G disposed in place,the space J associated therewith may be filled and the material packedbefore boring an adjoining shaft. In any event, too many of these shaftsshould not be bored and left unprotected the same time, for a pluralityof unprot cred shafts,

particularly adjoining shafts, might permit movement of the soil underthe pressure action of the adjoining structures.

After the sheet pilings G have been installed in position as shown inFig. 5, the excavation of .the area A may then be started. It should benoted that during the process of installing the pilings as shown in 5,some of the soil will probably have I owed or fallen intoadj oiningrelationship with the inside surface of these sheet piles. Under theseconditions, this soil would tend to react against the forces created bythe structure B. and serve, therefore, to decrease the degree ofdeflection of the sheet pilings G. The absence of the reactionary forcescaused by the removal of this material during e1;- cavation, may subjectthese sheet pilings to tendency'to throw these pilings out of alignment.It may therefore, be desirable as the excavation proceeds downwardly,and as the material is removed fromcontact with the inside surfaces ofsaid pilings, to compensate for such removal by bracing the intermediateportion of these pilings. For that purpose, the inside surfaces of thesheet pilings are braced by Wale pieces-K or other suita- 'ble bracingmembers disposed adjoining the inside surfaces-of the sheet pilings G,and urged into engagement with these sheet piling surfaces by means oftimber bracing members L as shown in Figs. 7 and 6.

The ability of the Wale pieces K to effectively sustain the pilingagainst further buckling, may also be pretested by driving wedge membersM between the walers and the inside surface of the sheet pilings.

As the excavation proceeds downwardly and additional wale pieces andbracing members are employed, the span of deflection of the pilings isreduced. That is to say, during'the original pretesting of the piling,the latter was free to flex throughout the entire span between thesurface waler and the toe hold, whereas the addition of other Walepieces during the process of excavation gradually cuts down this largedeflection span and subdivides it into a plurality of smaller spans,adding a further safety factor.

After the excavation of the region A has been accomplished, it may bedesired to line the excavated region with concrete as is customary inthe building of foundations. For that purpose, the sheet pilings maybe-retained in position, and a concrete wall formed adjacent the insidesurfaces of these pilings.

In Fig. 7, is shown the excavated region A in the process of being linedwith a concrete foundation. The concrete foundation wall N is shownconstructed adjacent the lower portions of the sheet pilings. After thiswall has been formed to a height close to'the lower bracing members, Land M, and has been hardened sufficiently to sustain the sheet pilingsagainst the inward pressure exerted by the soil on the outer surfaces ofsaid pilings, these lower bracing members may then be removed, the wallN, under these conditions compensating for the removal of these lowerbracing members. After these lower bracing members have been removed,the building of the wall N upwardly, is continued until the next bracingmember is reached. The new addition to the concrete wall N is thenpermitted to harden, and the next bracing members right above itremoved. This process is continued until the desired concrete foundationwall on the sides of the excavated region, has been formed. In thismanner, the pilings G are retained in braced position, during the layingof the foundation wall, and the soil outside the excavated areasupported'against settlement.

It should be noted that by means of my improved method, the installationof sheet pilings. is accomplished Without endangering .the foundationsof adjoining structures.

Also the method is simple and inexpensive, and does not create the messyand noisy conditions incidental to the installation of pilings bypresent methods.

From the foregoing description, it will be apparent that the method ispeculiarly effective for eliminating under-pinning and shoring whenmaking a foundation near astanding structure; Entirely aside from suchuse, however, the method of piling installing herein described, may becarried out for open trench workin the fields, and in locationswhere-the problem of lateral displacementof the soil is slight, sincethe method in any event, eliminates the need for the cumbersome,expensive apparatus which is usually difficult to transport intoout-of-theway localities.

The invention is susceptible of use in connection with various types ofsoil, but it has certain unique advantages when utilized in beach sand,particularly water-bearing sand which has been dewatered and which issubstantially incompressible and flows freely if rewatered. Among theseadvantages are the facts that driving of any type of piling in such sandis'extremely diflicult and that the sand is a particularly effectivemedium for packing and pretesting the piling and the tamping of thismaterial, which may be simply accomplished by'pouring water thereon. Iclaim:

1. The method of installing sheet pilings along a proposed line ofexcavation, which includes the steps of forming substantially verticalshafts along said line of excavation, disposing the sheet pilings insaid shafts, and disposing a filler in the cavities formed between theouter surfaces of said sheet pilings, and the corresponding outer wallsof said shafts.

2. The method of installing sheet pilings along a proposed line ofexcavation, which includes the steps of drilling substantially verticalshafts along said line of excavation, said shafts extending to a depthbelow the bottom of the proposed excavation, disposing the sheet pilingsin said shafts, and disposing a filler in the cavities formed betweenthe outer surfaces of said sheet pilings, and the corresponding outerwalls of said shafts.

3. A method of installing sheet pilings along a proposed'line ofexcavation, which includes the steps of forming shafts along theproposed'line of excavation, disposing the-sheet pilings in said shaftsinsubstantially vertical position, disposing a filler in the cavitiesformed between the outer surfaces of said sheet pilings, and thecorresponding outer walls of said shafts, and packing said filler sothat said filler exerts a lateral force on said sheet pilings suflicientfor said pilings to exert reactionary forces which balance the forcescreated by adjoining structures.

4. The method for installing sheet pilings along a proposed line ofexcavation, which includes the steps of forming along said line ofexcavation shafts, extending to a depth below the bottom of the proposedexcavation, disposing the sheet pilings in said shafts, and anchoringthe ends thereof in substantially vertical position with the lower endsthereof extending below the bottom plane of excavation, disposing afiller in the cavities between the outer surfaces of said sheet pilings,and the corresponding outer walls of said shafts, and packing saidfiller, so thatit exerts a lateral force on said sheet pilings.

5. The method for installing sheet pilings along a proposed line. ofexcavation, which includes the steps of forming substantially verticalshafts along the proposed line of excavation, disposing the sheetpilings in said shafts, filling the cavities formed between the outersurfaces of said sheet pilings, and the corresponding outer walls ofsaid shafts with loose material, and bracing the upper ends of saidsheet pilings to prevent these upper ends from moving out of alignment,and from deflecting inwardly towards the proposed region of excavation.

- 6. The method for installing sheet pilings along a proposed line ofexcavation, which includes the steps of drilling shafts substantiallyvertical along said line of excavation, disposing the sheet pilings insaid shafts, disposing a filler in the cavities formed between the outersurfaces of said sheet pilings, and the corresponding outer walls ofsaid shafts, and excavating and bracing the intermediate sections ofsaid sheet pilings at intervals against undue inward flexing as theexcavation uncovers said intermediate sections.

7. The method for installing sheet pilings along a proposed line ofexcavation, which includes the steps of drilling shafts substantiallyvertical into the soil, disposing the sheet pilings in said shafts, anddisposing the material recovered from said shafts into the cavitiesformed between the outer surfaces of said sheet pilings and thecorresponding outer walls of said shafts.

8. The method of constructing a foundation, which includes the steps ofdrilling shafts into the soil along the proposed line of excavation,disposing sheet pilings in said shafts with the bottoms thereof embeddedin the soil, disposing a filler in the cavities formed between the outersurfaces of the sheet pilings, and the corresponding outer walls of theshafts, anchoring the ends of said sheet pilings in position, excavatingand reinforcing the intermediate portions of the sheet pilings bybracing members as the excavation proceeds, building a concretefoundation wall in sections adjacent the sheet pilings, and removing thebracing members associated with said pilings, each concrete wall sectionextending vertically between adjacent reinforced portions of saidpilings, and being built and hardened successively, sai bracing membersbeing removed only when the adjacent concrete wall section just belowthem have hardened sufficiently to structurally compensate for theremoval of these bracing members.

Signed at Pleasantville, in the county of Atlantic and State of NewJersey, this 11th day of June A. D. 1931.

ANTHONY PAUL MILLER.

